1. Field of the Invention
The present invention relates to an inking ribbon cartridge intended for use in printers or similar machines such as, for example, typewriters or teleprinters.
2. Description of the Prior Art
Inked ribbon cartridges are well known in present day technology. One example of an inked ribbon cartridge is in French patent no. 2,155,539. As disclosed in that patent, the cartridge is formed by a casing for housing a rotatable delivery spool and take-up spool. To this end, the casing is provided with two openings to allow the ribbon the pass out to the exterior of the casing and with two projecting support members arranged at the points where the openings are siutated to guide the section of the ribbon lying outside the casing so that this section can be moved along a print line between the paper and the raised printing characters in relief of the machine. The inked ribbon is driven by two rollers between which the ribbon is engaged and which respectively drive and apply pressure to the ribbon. These two rollers are arranged in the casing on the same side as the opening situated near the take-up spool.
Such inked ribbon cartridges are not entirely satisfactory owing to the fact that, to wind the ribbon onto the take-up spool, they require a drive arrangement which is different from that which operates the drive roller. The result is that a machine which uses such a cartridge needs to be fitted with a particularly complicated and expensive drive mechanism. In addition, in such cartridges the ribbon has to be completely rewound, or even replaced, once it has been fully unwound from the delivery spool, which makes it necessary to stop the machine to perform the appropriate operations.
To overcome these disadvantages, a proposal has been made for an inked ribbon cartridge in which the delivery and take-up spools are dispensed with. The ribbon is stored in the casing and in a randomly folded state. In this cartridge the drive to the ribbon is provided by two toothed pinions between which the ribbon is engaged, with guiding and friction means being provided to enable the ribbon to feed out regularly from the casing. Such an arrangement is described and illustrated in French Pat. No. 2,188,505.
This cartridge, which is very suitable in cases where the ribbon is formed by a strip of one-shot carbon paper, proves difficult to use however when the ribbon is formed by an endless strip of fabric owing to the fact that such a ribbon, which is deformed in the course of its passages between the toothed pinions, eventually wears rather rapidly. There is then a danger of the ribbon arranging itself incorrectly in the casing and tangling or even breaking. In addition, such a cartridge appears totally unsuitable for use with an endless ribbon which, when formed from a material such as paper or plastics material for example, retains at least some traces of the deformation to which it is subjected. Also, and perhaps most objectionable is the tendency of the ribbon to stick to the friction rollers.